As I tried to explain above, many people say they can smell gas when its not actually gas they are smelling. One we dealt with turned out to be an overheating fridge motor for example!
Cat left a dead mouse once that had me thinking there might be a gas leak, on the other had had an odd musty smell in a cupboard where there was a capped off gas connection and that actually DID turn out to be a leak. Guess noses aren't good.